A cobpobation



May 31, 1927.

H. C. HUBBELL IGNITION SYSTEM Fon BURNERS Filed April 2, 1925 2Sheets-Sheet 1 INVEN TOR.

A TTORNEYS.

IGNITION SYSTEM FOR BURNERS Filed April 2. 1925 2 Sheets-Sheet 2 IN VENTOR.

A TTORNEYS.

Patented May 31, 1927.

UNITED STATES A 1,630,702 PATENT oFFlcE.

HARRY C. HUBBELL, F WEST'SPBINGFIELD, MASSACHUSETTS, ASSIGNO'B TO WIGOELECTRIC! COMPANY, OF WEST SPRINGFIELD, MASSAQHUBETTB, A CORPORATION OFMASSACHUSETTS.

IGNITION SYSTEM FOR BUBNEBS.

Application tiled April 2, 1925. Serial I0. 20,949.

This invention relates to improved means for controlling the ignitionmeans of a burner and, while the invention is. capable of other andgeneral applications, it has been developed and is particularly suitablefor use in connection with oil burners.

The invention will be disclosed in a form developed for use inconnection with electrical or spark ignition means and as adapted to cutin and cut out such an ignition means whenever necessary. In certainrespects, as will be evident from the description to follow, theinvention is not restricted to the use of s ark ignition means andmight, for examp e, be made to alternately reduce andenlarge the flameof a gas pilot at proper times, according to the necessity therefor asmanifested by the presence or lack of a flame from the burner. Thereference hereinafter to s ark ignition is, therefore, not necessarilylntended to exclude all other forms of ignition means although the sparkignition means is referred.

The pro lem of this invention may be very simply stated. It is to cutout the ignition means as soon as the burner has been ignited and torender the ignition means again available for the igniting function assoon as the rburner stops. The solution'of the problem is not so easy aswill be evident from a study 2 of the prior art, .which shows that theproblem has been 'attacked from many widely differing ang'les. Among themore common forms of control, found in the prior art is that whichfunctions according to time. That is the ignition is cut in on startingthe flow of fuel to the burner and remains in for a definite timeinterval. This is not as satisfacto as it should be because it is en- 40tirely possible for the time interval to elaise lwithout i itionactually occurring. he ignition slgilduld be stopped only after its workhas actually been accomplished, as manifested by a liamel issuing fromthe burner, which seems to require a control responsive to burner heat.A representative t of such heat control is the flame type t ermostatfound in the rior art as operatin a switch or valve. guch a'thermostatwhi e apparently suitable from theoretical considerations, does notprove satisfactory in practice because it is not suiicientlyrquickacting for the purpose. The difficulty arises because the thermostat issubjected to very because it has not cooled sufficiently and oil will bethrown into the fire box to be later ignited with possible disastrousresults. While all sorts of precautions have been taken to cope withsuch emergencies, in.- stances of ex losions directly traceable to slowaction o an ignition controlling thermostat have occurred. Thethermostat is therefore not wholly reliable and does not adequately meetal the conditions which must be met in practice to insure safe andreliable automatic operation of an oil burner.

The object of this invention is to provide a controlling device which isresponsive to heat, as is the thermostat, but which will function toquickly cut out the ignition means `once its work has been accom lished,as manifested by the presence of me at the burner and which after theburner has stopped w' 1 a ain cut in the ignition simultaneously 'wi thestarting of the burner and. without any delai. 4

In attaining this o ject, a novel form of control device is arranged ina1. electrical circuit which also includes an' electrically operateddevice for cutting in and out the ignition means. 'The control deviceincludes an air p and through which no current flows w en the burner isnot ignited. The invention depends, it is thought, on the ioni` zationof the air between the electrodes of the-control device caused by theheat from the flame of the ignited oil burner and the practical resultis that, on such a condition, current sufficient to o rate said deviceflows through the circuit. its simplest form the control device consistsoftwo spaced electrodes with an air gap therebetween and it ma be anordinary spark plug.

Ih addition tothe control device, which Other features and advantageswill appear from the following description and in the illustrativeembodiment of the invention in the accompanying drawings, in which 1 isa fragmentary sectional elevatona view of an automatically controlled oiburning furnace showing the disposition of the control device andignition means therein; and

Fi 2 is a diagr'ammaticalview showing the e ectrical connections forcontrolling the burner, an electrical ignition system and a controltherefor.

Referring to these drawings: the auto--y matic oil burner may obviouslyVbe of any suitable type and that shown herein is given solely by way ofillustrative exam le. There are many other types which woul be equallysuitable and with which my invention could as readily be used. As shown,the oil burner is of the centrifugal type and involves a cup atomizer 5carried on the upper end of a hollow vertical shaft 6 through which oilis drawn up to the atomizer from a reservoir 7 by the action ofcentrifugal force. Shaft 6 is driven, as by spiral gears 8, from ahorizontal shaft 9 connected to the armature of an electric motor 10.The latter the reservoir and theupporting casing for shaft 6 are shownas mounted on a common bed plate 11, one end of which extends into theash pit 12 of furnace F. The fire box 13 has a central opening 14 in itsbed'15 through whlch shaft 6 extends and through which combustionsupporting air enters. The oil, in the form of a fine mist or 'spra isthrown outhorizontally from cu 5 an is adapted to be ignited from a sparplug 16, suitably su ported as shown.

e control device, which as stated may be a s ark plug, is shown in thatform at 17A an includes an air gap 18 between two electrodes 19 and 20.The control device may be supported like the spark plug and I prefer toarrange vit as shown `at a distance therefrom.

The oil burner motor is arranged to be started and sto ped underthermostatic control, desirablygrom a room thermostat actin in anysuitable manner tooperate a switc in the motor circuit. For convenience,the room thermostat and switchL have tact 30 which is stationaril beenshown in conventional form at 21 and 22, respectively, in Fig. 2 and theswitch is interposed in one of the supply wires 23 and 24 leading from asuitable source of alternating current to the motor 10. Other usualsafety devices, in common use ywith oil burners, may be interposed inthe circuit to motor 10 and I have not attempted to illustrate more thanthe fundamental parts necessary to a proper understanding 4of thisinvention.

The ignition system comprises, in addition yto spark plug 16, atransformer T, of which 25 represents the core, 26 the primary, 27thesecondary and 28 an auxiliary secondary for use-'in connection withthe control device 17. The rimary winding 26 is connected in circuitwith L'the supply wires 23 and 24 but beyond the motor l-and'includes aswitch, comprisin the contacts 29 and 30 .by means of whic the primarywinding may be cut out of circuit without stopping motor 10. Oneterminal of the primary is connected directly to wire 23 and the otherterminal is connected by a wire 31 to consupported, as from aninsulating standar 32 from a bed plate 33. Contact 29 is mounted on ametallic lever 34, which is connected to wirel24 and is pivotallysupported at one end, as from an insulating standard 35, also mountf edon' bed 33. A- spring 36 urges lever 34 upwardly and tends to holdcontacts 29 and engaged. The secondar`y27 is connected b wires 37 and 38to the electrodes of spark p ug 16. It will be seen that there are twoswitches controlling the iprimary winding of4 -the transformer T and tus the high tension current to s ark plu 16` When switch 22 opens the oter switc closes, as will appear, so that when the thermostat 21 causesswitch 22 to close' and start the oil burner motor 10 it also causes theenergization of the transformer and sparks are produced across theelectrodes of plu 16 to ignite the oil. In the event of ignitlon, thecontacts 29 and 30 are caused to se arate, as will appear, and cut outthe rimary of the transformer, thereby stoppmg the ignition means.

The separation of contacts 29 and 30 is effected b electrical meansadapted to be energized y current from the auxiliary sec- 'ondary 28,which current is permitted to.

flow, at least to an extent suflicient to perform the function, onlywhen a degree of heat, such as that due to the llame from the oilburner, exists in the fire box. The lever 34 has attached thereto aluarmature 39 which is adapted to be attracted by a solenoid 40, mountedon base 33. One terminal .of solenoid 40 is connected by a wire 41 toelectrode 20 of the control lug 17' and the other terminal is connectedby a wire 42 to one terminal of the auxiliary secondary 28. The otherterminal of the latter is con i lows nected to the wire 37, to which theelectrode 19 of the control plug is also connected. This wire 37 may begrounded, as indicated. On energization of solenoid 40 a quick, strongdownward pull is imparted to lever 34 and thereby the contacts 29 and3() are separated, which cuts out thc primary of the transformer andthus cuts off the current flowing 'to solenoid 40. To hold the switchlever 34 in its lower position, a second solcnoid 43 'is rovided whichsimilarly acts on a second p unger 44 connected to lever 34. Thissolenoid -is bridged across the suppl wires 23 and 24 and controlled bya switc i comprisinv two contacts 45 and 46, which are normally o en butare adapted to be envaged by the grst downward movement of ever 34. Thecontact 45 is fixed to lever 34 and thus connected to wire 24. y Wire 23is connected by a wire 47 to one terminal of solenoid 43 and the otherterminal of the latter is connected b a wire 48 to contact 46. Thelatter is slida l mounted in a standard 49, insulated from tied 33, andis urged upwardly by a spring 50 to the limit permitted by a stop 51.The contacts 45 and 46 do not quite touch so that the circuit tosolenoid 43 is normally open but can be closed quickly, on the rstdownward movement of lever 34. The solenoid 40 gives the ipick, strongpull necessary to cause a quie and sharp separation of contacts 29 and30. The solenoid 43 then comes into play to hold the contacts separated,even after current ceases to/flow in solenoid 40, and solenoid 43 is sodesigned as to consume a veryA small amount of power, say five watts ort ereabouts. It can, therefore, be left in circuit for long in tervalswith an exceedingly small expense for power. The solenoid 40, being usedonly intermittently and for intervals of short duration, can be wound togive the desired results and it matters little if more power isconsumed. The solenoid 43 remains energized as long as the motor 10continues to operate but as soon as the thermostat 21 opens switch 22 tostop the motor it also opens the circuit to solenoid 43. The spring 36then restoresthe lever 34 and engages contacts 29 and 30. This actionensues 1mmediately 'after the current is cut off from motor 10 by the oening of switch 22 and on again closing e latter the primary oftransformer T 1s supplied with current as quickly as is motor 10.Consequently, the motor and ignition means start simultaneously andthere can be no delay between the operation of these two elements. Atthe same time the control device causes the i ition means to be cut outimmediately a r the burner is ignited. y

The o ration ma be summarized as folen the o' burner is not working theparts are in the relative positions illustrated in Fig. 2. The ignitionmeans is liketical result is an intense wise idle and no current isbeing consumed thereby oi' by the switch holdin solenoid 43. As soon asoperation of the oil ui'ner is required, as manifested b thermostat 21,switch 22 is closed by the atter. The motor 10 is thus started and oilis discharged into the tire box by the atoniizer. At the same time, thetransformer is supplied with current and ignition s arks are produced atthe spark plu 16. T ie spray of oil from the atomizer ollows thestarting of the motor and is at least slightly deferred while thc sparksare produced at the plug simultaneously with the starting of the motor.Consequent] the ignition means is available an instant before it isneeded.

By preference, the secondary 27 is designed to give a high voltagebefore the spark starts so as to insure its starting and, after thespark is jumpin at the plug, the current is such that the en s of theelectrodes are brought to a glowing temperature. The result is virtuallyan arc, as distinguished from the ordinary jump s ark, and the praceatwhich is sufficient to gasify fuel oils of low volatility, wherebyignition of fuels, diliicult to ignite by a simple high tension s ark,is insured. The use of such an electrica ignition means, demands thatthe same be cut out immediatel that itis no longer needed to minimizeestructiv" effects on the electrodes of the plug. There is thus anadditional reason, over the ordinary reason of needless waste of enerfor cutting out the ignition means prompt y.

VThis result is insured by the special control device which is arrangedto respond only to the high temperature due to the oil burner flame.This device accomplishes its work instantaneously, or at leastapparently so, and withprecision and certainty. The heat from the oilburner ame increases the conductivity of the air gap between theterminalsof the control plug and current ows to the solenoid to a degreesufiicient to impart a quick strong pull to armature 39. The contacts 29and 30 are immediately separated, thereby openin the primary circuit ofthe transformer ang cutting out of action both the ignition secondaryand the secondary used to supply the control plug. At the same timecontacts 45 and 46 are en aged to energize the solenoid 43 which holdsthe contacts 29 and 30 separated until the oil burner motor stops. Atthat time switch 22 opens and contacts 2Q and 30 immediately engageagain, thus throwing the control of the i nition means back on thethermostat switc so that it will be instantly available when motor 10 isa ain started.

By analo it will be readily apparent to those skille in the art that theignition controlling means may readily be adapted to operate a valve aswell as the switch dislll) closed, whereby the control may have a fieldof service in connection with ignition means other than of an electricalcharacter.

While in the precedin description the control device is describe as anair gap, it is recognized that the preferred form of the invention maybe varied in numerous ways and still operate in essentially the samebroad manner and upon the same broad principle. The air gap is the bestexample of a control device which when subjected to heat will Afunctionin the manner above set forth but it is recognized that other controldevices may he used in the same general manner, wherefore this inventionis not to be restricted lo the particular form herein specifically setforth.

The invention turns largely on the particular control device as combinedwith other elements to effect the results disclosed. This device is thekry to the successful solution of the ignition control problem becauseit can be made as sensitive as need be and instantly responsive to theoil burner flame. It has been demonstrated that the heat from a lightedmatch held in proximity to the gap of the control plug will cause animmediate opening of, a switch by electrical means. The control deviceis thus the governing element in a broad combination with other elementsof an ignition system. It follows that the details of such s stem andthe particular types of the broa elements of the combination may bevaried as desired and that the details disclosed are exemplary incharacter. It is the intention to claim the invention in the broadestpossible legal manner.

What I claim is:

l. In combination, a burner, an ignition device therefor having anactive condition for ignition of fuel from the burner and an inactivecondition, means to automatically start and stop the burner and to.render the ignition device active simultaneously with the starting ofthe burner, means to render the ignition device inactive independentlyof the first named means, electrical means to operate the last namedmeans, a source of electrical energy for said electrical means,

a control device associated` with the burner` and including twoterminalswith an air gap therebetween, and a series circuit including saidsource, electrical means and terminals, said gap adapted to be heated bythe burner flame and when so heated to permit suflicient current to Howin said circuit to operate said electrical means.

2. ln combination, a burner, an ignition device there-for having anactive condition for ignition of fuel from the burner and an inactivecondition', means to automatically start and sto the burner and torender the ignition device active simultaneously with the starting ofthe burner, means to render the ignition device inactive independentlyof the first named means, electrical means to operate the last namedmeans, a source of electrical energy for said electrical means, acontrol device associated with the burner Vand including two terminalswith an air gap therebetween, and a circuit including said source,electrical means and terminals, said air gap adapted to be heated by theburner flame and when so heated to permit suicient current to flow insaid circuit to operate said electrical means, and means operable by thefirst named means when it sto s the burner to reset the means wherebytlie ignition device was rendered inactive.

'3. In combination, a burner, automatic means to start and stop thesame, electrical ignition means therefor includin an electrical circuitarranged to be c osed and opened by the starting and stopping, resvectively, of the burner under the contro of said automatic means, saidcircuit also including a normally closed switch, electrically operatedmeans adapted when energized to open said switch, and a control devicearranged in circuit with said electricall erated means and a suitablesource o electricity, said device includin two spaced terminals with anair gap t erebetween and so located that said medium is heated by llamefrom the burner, said medium when so heated becoming conductive andpermitting flow of` current across said terminals to energize saidelectrically operated means and open said switch to cut out saidignition means.

4. In combination, a burner, automatic means to start and stop the same,electrical ignition means therefor includin an electrical circuitarranged to be c osed and opened by the starting and stopping,respectively, of the burner under the control of said automatic means,said circuit also including a normally closed switch, electricallyoperated means adapted when energized to open said switch, a controldevice arranged 1n circuit with said electrically operated means and asuitable source of electricity, said device including two spacedterminals with an air gap therebetween and so located that said mediumis heated by llame from the burner, said medium when so heated becomingconductive and ermitting liow of current across said termlnals toenergize said electrically operated means and open said switch to cutout said ignition means, and means to hold said switch open until theburner is stopped by said automatic means and to then permit said switchto be closed.

5. In combination, a burner, spark elec- `trodes positioned Ato ignitethe fuel from the burner, a transformer, .a secondary. circuit from thetransformer including said electrodes, a primary clrcuit from the transman Np. 1,630.70@

former including a self closing and normally closed switch therein,automatic means for starting and stopping the burner and for closing andopening said primary circuit, electrical means adapted w en energized toopen said switch, a second set of spaced electrodes adjacent saidburner, and a secondary circuit from said transformer including saidelectrical means and said second set of electrodes.

6. In combination, a burner, spark electrodes positioned to ignite thefuel from the burner, a transformer, a secondary circuit from thetransformer including said electrodes, a rimary circuit from thetransformer inc udin a selfclosing and normally Vclosed switch t erein,automaticlmeans for starting and stopping the burner and for closing andopening said primary circuit, electrical means adapted when energized toopen said switch, a second set of spaced electrodes adjacent saidburner, a secondary circuit from said transformer including saidelectrical means andsaid 'second set of electrodes, a second electricalmeans adapted when energized to hold said switch open, a supply clrcuittherefor controlled by said automatic means and ai switch in the lastnamed circuit adapted to be closed by the opening of the first switchand opened by the closing of the latter.

7. The combination with an oil burner, an electric motor to-drive thesame and a thermostat o rated switch to start and stop the motor, oSpark electrodes for igniting the oil from the burner, a transformer toproduce sparks across the electrodes and connected in circuitwith saidmotor so as to be subject 'to control by said switch, a, self closingvswitch also. in circuit with the transformer and adapted when opened to.cut out the transformer without stopping the motor, a second pair ofspaced electrodes arranged adjacent the humor, electrical means ada tedwhen energized to 'pen the self closing switch, and4 acirqkmthetransformer ctnrirlarr or CORRECTION.

electric motor to drive the same and a thermostat operated switch tostart and stop the motor, of spark electrodes for igniting the oil fromthe burner, a transformer to produce sparks across the electrodes andconnected 1n circuit with said motor so as to be subject to control bysaid swltch, a self closingswitch also in circuit with the transformerand adapted when opened to cut out the transformer without stop ing themotor, a second pair of spaced e ectrodes arranged adjacent the burner,electrical means adapted when energized to open the self closing switch,and a circuit from the transformer including said electrical means andsaid second pair of electrodes, a second electrical means adapted whenenergized to hold the self closing switch open, a circuit from the motorcircuit connected in shunt therewith and adapted to sup ly said second,`electrical means, and a switc 1n said shunt supply circuit adapted to beclosed by the opening ofthe self closin switch.

9. In combination, a urner, means for startinr and stopping the same, anignition device thaving' an active condition for igni tion of the fuelfrom the burner and an inactive condition, means for rendering said device active simultaneously with the starting of the burner, electricalmeans effective when energized to render 'said device inactive and aseries electrical circuit including said elec trical means with an airgap and a source of high potential, whereby the air gap forms a reak insaid circuit, said air gap bein subjected to the heat from the burner anwhen heated therely permitting a flow of current across sai gap to saidelectrical means.

In testimony whereof I have aiiixed my signature.'

HARRY C. HUBBELL.

Granted Maj' `3l, 1927, to

' HARRY c. HUBBELL.

It ie hereby certified that error appears in the printed specificationof the eboye numbered p'etent requiring correction as follows: Page 4,line 5S, claim l, before ltlle word"'ap" insert the word "air"; page 5,line 86, claim 9,1before the word "said" inse-rt the word "energize";and that the said Letters Petent should be read with these correctionstherein that the same may conform te the record of the case in thePatent Office.`

Seel.

signed dialed um 21st da; of June, A.: n. 1921.

M. J. Moore, I Acting Commissioner of Patente.

man Np. 1,630.70@

former including a self closing and normally closed switch therein,automatic means for starting and stopping the burner and for closing andopening said primary circuit, electrical means adapted w en energized toopen said switch, a second set of spaced electrodes adjacent saidburner, and a secondary circuit from said transformer including saidelectrical means and said second set of electrodes.

6. In combination, a burner, spark electrodes positioned to ignite thefuel from the burner, a transformer, a secondary circuit from thetransformer including said electrodes, a rimary circuit from thetransformer inc udin a selfclosing and normally Vclosed switch t erein,automaticlmeans for starting and stopping the burner and for closing andopening said primary circuit, electrical means adapted when energized toopen said switch, a second set of spaced electrodes adjacent saidburner, a secondary circuit from said transformer including saidelectrical means andsaid 'second set of electrodes, a second electricalmeans adapted when energized to hold said switch open, a supply clrcuittherefor controlled by said automatic means and ai switch in the lastnamed circuit adapted to be closed by the opening of the first switchand opened by the closing of the latter.

7. The combination with an oil burner, an electric motor to-drive thesame and a thermostat o rated switch to start and stop the motor, oSpark electrodes for igniting the oil from the burner, a transformer toproduce sparks across the electrodes and connected in circuitwith saidmotor so as to be subject 'to control by said switch, a, self closingvswitch also. in circuit with the transformer and adapted when opened to.cut out the transformer without stopping the motor, a second pair ofspaced electrodes arranged adjacent the humor, electrical means ada tedwhen energized to 'pen the self closing switch, and4 acirqkmthetransformer ctnrirlarr or CORRECTION.

electric motor to drive the same and a thermostat operated switch tostart and stop the motor, of spark electrodes for igniting the oil fromthe burner, a transformer to produce sparks across the electrodes andconnected 1n circuit with said motor so as to be subject to control bysaid swltch, a self closingswitch also in circuit with the transformerand adapted when opened to cut out the transformer without stop ing themotor, a second pair of spaced e ectrodes arranged adjacent the burner,electrical means adapted when energized to open the self closing switch,and a circuit from the transformer including said electrical means andsaid second pair of electrodes, a second electrical means adapted whenenergized to hold the self closing switch open, a circuit from the motorcircuit connected in shunt therewith and adapted to sup ly said second,`electrical means, and a switc 1n said shunt supply circuit adapted to beclosed by the opening ofthe self closin switch.

9. In combination, a urner, means for startinr and stopping the same, anignition device thaving' an active condition for igni tion of the fuelfrom the burner and an inactive condition, means for rendering said device active simultaneously with the starting of the burner, electricalmeans effective when energized to render 'said device inactive and aseries electrical circuit including said elec trical means with an airgap and a source of high potential, whereby the air gap forms a reak insaid circuit, said air gap bein subjected to the heat from the burner anwhen heated therely permitting a flow of current across sai gap to saidelectrical means.

In testimony whereof I have aiiixed my signature.'

HARRY C. HUBBELL.

Granted Maj' `3l, 1927, to

' HARRY c. HUBBELL.

It ie hereby certified that error appears in the printed specificationof the eboye numbered p'etent requiring correction as follows: Page 4,line 5S, claim l, before ltlle word"'ap" insert the word "air"; page 5,line 86, claim 9,1before the word "said" inse-rt the word "energize";and that the said Letters Petent should be read with these correctionstherein that the same may conform te the record of the case in thePatent Office.`

Seel.

signed dialed um 21st da; of June, A.: n. 1921.

M. J. Moore, I Acting Commissioner of Patente.

